Salivary Cystatin S in Children With Early Childhood Caries in Comparison With Caries-free Children; Statistical Analysis and Machine Learning

Background: Early childhood caries is the most common infectious disease in childhood, with a high prevalence in developing countries. Recognition of the factors affecting early childhood caries and its pathophysiology, allows better control of disease. Cystatin S as one of the salivary proteins, has an important role in pellicle formation, tooth re-mineralization and protection. The aim of the present study is to assess salivary cystatin S levels and demographic data in early childhood caries children in comparison with caries-free ones using statistical analysis and machine learning methods. Methods: : A cross-sectional case-control study was undertaken on 20 cases of early childhood caries and 20 caries-free children as a control group. Unstimulated whole saliva samples by suction method was collected. Cystatin S concentrations were determined using human cystatin S ELISA kit. A checklist was collected for each participant about the demographic characteristics, oral health status and dietary habits by interviewing parents. The regression and receiver operating characteristic (ROC) curve analysis was done to evaluate the potential role of cystatin S salivary level and demographic using machine learning and statistical analysis. Results: : The mean value of salivary cystatin S concentration in early childhood caries group was 191.55±81.90 (ng/ml) and in caries-free group was 370.06±128.87 (ng/ml). T-test analysis showed that there is a statistically significant difference between early childhood caries and caries-free group in salivary cystatin S level (p: 0.032). Investigation of area under the curve and accuracy of ROC curve revealed that logistic regression model based on the salivary cystatin S levels and birth weight had most and acceptable potential for discriminating of early childhood caries from caries-free controls. After that the machine learning models and finally salivary cystatin S levels had more capability for differentiation of early childhood caries from caries-free controls. Conclusion: Salivary cystatin S in caries-free children was higher than the children with early childhood caries. Therefore, cystatin S protein can be used as a biomarker for early prediction of early childhood caries, furthermore cystatin S is a protective factor against dental caries.